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EP 3 673 310 A1

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(43) Date of publication: 01.07.2020 Bulletin 2020/27 (21) Application number: 18848231.9 (22) Date of filing: 27.08.2018

(51) International Patent Classification (IPC):  G02B 6/44(2006.01) H01B 11/22(2006.01) H01B 7/282(2006.01) G01L 1/24(2006.01) (86) International application number: PCT/US2018/048044 (87) International publication number: WO 2019/040926 (28.02.2019 Gazette 2019/09)

(84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR Designated Extension States: BA ME Designated Validation States: KH MA MD TN (30) Priority: 25.08.2017 US 201715686270 (71) Applicants: Services Pétroliers Schlumberger 75007 Paris (FR) FR  Schlumberger Technology B.V. 2514 JG The Hague (NL) AL AT BE BG CH CY CZ DE DK EE ES FI GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(72) Inventors: WILSON, Colin Allan Houston, Texas 77077 (US) HARTOG, Arthur Cambridge Hampshire CB3 0EL (GB) (74) Representative: Schlumberger Intellectual Property Department  Parkstraat 83 2514 JG Den Haag 2514 JG Den Haag (NL)